Method for controlling the efficiency of mercury rectifiers.



W. TSCHUDY.

METHOD FOR CONTROLLING THE EFFIGIENCY 0F MERCURY RECTIFIERS. APPLICATION FILED APR-15.1913.

1,189,887. Patnted Ju1 4, 1916.

hu v w an" UNITED STATES PATENT OFFICE. 8

WILLIAM TSCHUDY, OF LYNN, MASSACHUSETTS.

METHOD FOR COIVTROIJLING THE EFFICIENCYOF MERCURY RECTIFIERS.

My invention relates to the control of the efficiency of mercury rectifiers which, so far as I am aware, has not been controllable up to the present time.

Rectifiers of this type have heretofore been simply connected to the source of al'- ternating current, and the rectified current has been received by the current consumer such as storage batteries or the like, irrespective of the efficiency of the rectifier.

It is the object of my invention to reduce the resistance of amercury vapor rectifier to the best possible minimum by selecting a particular vapor pressure on which to operate.

My invention also comprises the method for regulating the amount of watts consumed in the compartment of a gasor vapor electric apparatus, especially of a rectifier of large capacity, by changi g the pressure in the compartment throng admitting or withdrawing the gaseous medium or other suitable equivalent means.

It also comprises'a method of changing the wave formed in the compartment of a gas or vapor electric apparatus, especially of a rectifier of large capacity by varying the pressure in the compartment. The improvement in the efficiency of a glassrectifier tube by regulating the pressure isapproximately from 7 to 10 per cent. In

case of large rectifiers Where the regulation is particularly important, the efficiency may be improved more than the I above amount.

By my novel method which I shall de- Specification of Letters Patent. Pat 11 e4; fig 4 915 I Application filed April 15, 1913: Serial No. 761,315. l L U scribe presently it is possible to control the efficiency of such rectifiers such that it can be easily adjusted to the maximum, possible efliciency.

In the accompanying drawings, Figure 1 represents diagrammatically a rectifier and its circuit connection, and Fig. 2 represents a curve diagram of the current and tension curve for one period.

Referring to Fig. 1 C represents the mercury rectifier which is connected at its two anodes F and G with the two terminals A andB of an auto transformer, which in turn is connected at L L with the line L from which the alternating current is sup plied. The mercury cathode Q is connected by way of the direct current consuming device' D with the middle terminal M of the transformer. As soon as the vaporization of mercury has started current canflow inthe rectifier from the anode F to the mercury cathode Q during oneshalf period. If now,- by suitable means the momentary values of the potential P which exists between anode Rand cathode Q, and also the momenmentally during an entire period T, which is denoted with T, on the abscissa X in Fig. 2, the formv of the current and tension curves is obtained, for instance as is shown in'Fig'. 2. As previouslymentioned the timeis represented by the abscissa X and'the values of the current I and the tension P are represented by the Y'ordinates.'

The momentary values of I and 'P are entered in this coordinate system during one period T. In Fig. 1 the instruments by which I and P are measured are correspond tary values of the current flowing from terminal A tothe anode F are observed experi 2%; intense? If now, the tension curve, which has an unsymmetrical course relatively to the time axis X, is mathematically analyzed an equation is obtained of the form:

Ap=P +P sin 2rnt+P sin' 2(21rnt) +P sin 3(2ivmt) v or Ap=P +EP sin ic 21m, wherein k 1, 2, 3, etc.

In this equation P represents the constant member (direct current component) and P the amplitude of the several waves.

5 Since the current curve 1 runs likewise tion has the form:

wherein J represents the constant member (direct current component)v andJ J etc., represent the amplitudes of the several waves, and a represents the dlfi'erence 1n unsymmetrically to the time axis X its equaphase between the first tension curve and the first current curve a the difference between I 10 the second tension curve and the second current curve, etc.

Generally the above equation may be written of the form:

t=J an sin (7C.21r1tta wherein k= 1, 2, a, Btu.

If new one half of the voltage consumed in vessel C is denoted with 2% this loss amounts to 2-- It now the values of z and p as expressed by the above formulas are inserted in this equation we obtain t. 0 =d lP +J P =+J P ciency depends upon the pressure in the vessel.

If now, according to the results thus obtained the pressure invessel C is suitably varied the tension and current curve and simultaneously the efficiency of the rectifier Thus by analyzing any of the tension and current curves which may be experimentally obtained the influence of the several members of the last e uation on the loss of 20 eiiiciencyin the vessel% may be ascertained.

From a certain current and tension curve obtained by experiment as an example and by subsequently figuring the difierent values may be brought about for instance by pump E ing a gaseous medium into the vessel C, or

5 the by withdrawing it therefrom as the case may be, by means of a pump N or other suitable equivalent means. Thus it is possible to ad according to the formula for 5 lowing result was obtained:

cos a I o: 5 1 5 7 0. gust theloss in such rectifieis to a minimum P +413 2 3 by varying the gas pressure in the rectifier.

lhe consumption of energy is preferably de- J 1 i a2 =65,8 J P w =7,8 termined b a wattmeter in the usual wellknown manner.

From this example it may be seen that The adjustment of the efiiciency loss may can be varied. The variation of gas pressure the loss of eificiencydn vessel C depends I largely upon the curve form, since even the fourth member of the equation (not chtained here) has an effect on the amount of loss in efficiency.

I have now determined by experiment that the curve form depends upon the gas pressure in vessel C. Thus also the loss of ethbe of great value if the apparatus is for instance connected to a source of alternating current, the curve form of which is very unfavorable with regard to the efficiency loss; thus by subsequently regulating the vacuum in the rectifier tube the curve form of the tension and the current may be influenced in such manner that the loss in efiiciency is a minimum. For instance, in case of a very sharp peak curve of the source of energy the consumed energy of the tube may amount to 210 watts, while in case of a sine curve at the same tension and the same load and" otherwise under the same conditions, the consumed energy may only amount to 138 watts.

What I claim is: 1. The method of controlling the wave form transmitted by a mercury vapor apparatus which consists in changing the physical condition of the vapor in said apparatus. 2. The method of controlling the wave form transmitted by a mercury vapor appa- I 3, The method of controlling the efficiency of vapor rectifiers which consists in supplying a varying current flow to the rectifier and varying its form factor by varying the pressure or density of the vapor of the recti- \VILLIAM TSCHUDY.

Vitnesses:

TIMOTHY A. OLEARY, PHILIP A. KILBY. 

